这两个语句有什么区别呢?
这两个语句的区别在于:
var result = from c in context.CustomerEntities
join p in context.ProjectEntities on c.Pk equals p.CustomerPk
where p.Entered > DateTime.Now.AddDays(-15)
select c;
并且
var result = from c in context.CustomerEntities
join p in context.ProjectEntities on c.Pk equals p.CustomerPk
where p.Entered > DateTime.Now.AddDays(-15)
select new (c.Company, c.Entered, c.pk);
这些语句中是否存在与性能相关的问题?(为简单起见,c仅包含这三列。)
谢谢。